Sulphate of Zinc. ZnO, SO3 + 7 HO. White Vitriol. White Copperas, &c. Comp. Oxide of Zinc 28.22, Sulphuric Acid 27.88, Water 43.90, in 100 parts; or 1 Eq. Oxide of Zinc = 40.5, + 1 Sulphuric Acid = 40, + 7 Water + 63 = 143.5, Eq. Wt.

Med. Prop. and Action. Tonic, astringent, and anti-spasmodic, in doses of gr. j., gradually increased. In doses of gr. x. - gr. xx., it proves emetic, acting promptly and effectually, and leaving little subsequent depression; it is consequently much used in cases of poisoning by narcotic substances. Besides its tonic and astringent properties, which are evident only when persevered in in small and repeated doses, it appears to act powerfully as a nervine, and proves highly serviceable in spasmodic affections having their origin in derangement of the nerves or nervous centres (see Chorea). In excessive doses it is an irritant poison. Externally, it is an astringent and stimulant; it is used in the form of collyrium, wash, or lotion (gr. j. - x. or more, ad Aq. fl. oz. j.). If its internal exhibition be continued for too long a period, Dr. Graves observes, that it occasions marasmus. As a caustic, its claims are advocated by Prof. Simpson.* In a dried or anhydrous state and finely levigated, he characterises it as a powerful and very manageable caustic when applied to an open or diseased surface: it does not act where the epithelium is entire. He likewise uses it in the form of paste (Dried powder j., Glycerine f 3j.), or ointment (j. - Axung. 3ij.). Its advantages over other caustics are said to be - 1. Its powerful escharotic action. 2. The rapidity of its action. 3. Its great simplicity and manageableness. 4. Its facility of application. 5. Its non-tendency to deliquesce, or spread. 6. Its perfect safety; and 7. Its efficacy. Where the skin is entire, he recommends a caustic made by saturating strong Sulphuric Acid with dried and powdered Sulphate of Zinc.§

Dose: as a tonic, gr. j., gradually increased to gr. v., or more; as an emetic, gr. x. - gr. xxx.

Incompatibles. Alkalies and their Carbonates; Earths, Sulphurets; Acetate of Lead; Nitrate of Silver; Chloride of Barium; and vegetable astringent infusions.

2854. Therapeutic Uses

In Chorea, the Sulphate of Zinc proves highly effectual. Dr. Babington || states that he has employed it in numerous cases, and that he has found it uniformly efficacious. He commences with small doses, but he found that the good effects are seldom perceptible until gr. xij. or xiv. are taken thrice daily. By gradually increasing the quantity, a single grain at a time, even larger doses than these may generally be employed, without exciting nausea, and with the best effects. "I have," he adds, "known 3ss. doses, thrice a day, taken for several weeks in succession." It cannot, however, be borne by all stomachs; when sickness occurs, it should be discontinued. In thirteen cases thus treated at Guy's Hospital, twelve recovered. Dr. Hughes* employed it in sixty-three cases; of these, forty-five were cured, two relieved, and sixteen received no benefit. The dose employed was small at first, and gradually increased until gr. xxxvj. were taken, thrice daily. It caused no sickness. Other cases have been successfully treated by Drs. Addison and Barlow. Dr. Golding Bird believes that Zinc has a peculiar and specific influence on the nervous matter. The trials by Dr. Stone do not tend to confirm the high character given it by others.

* Lectures, vol. ii. p. 857. Diseases of the Skin, Ed. 1851, p. 265. Med. Times and Gaz., Jan. 17,

§ Ibid., Feb. 5, 1857.

|| Guy's Hosp. Reports, Oct. 1841, and Oct. 1845.

2855. In Epilepsy, it has also been found successful,§ although not so uniformly as in Chorea. It is a remedy of long-standing repute, but is generally inferior to the Valerianate. It should be commenced in small doses, gradually increased in the manner advised in the last section.

2856. In Hysteria depending upon debility, the Sulphate of Zinc will be found to agree with many females better than the preparations of Iron, causing less irritation. One grain, combined with the Extract of Gentian, may be given twice or thrice daily.

2857. In Angina Pectoris, the salts of Zinc, particularly the Sulphate, have sometimes proved successful when persevered in during the intermissions. A case illustrative of its good effects is related by Dr. Perkins.)) In Spasmodic Asthma, it has also appeared, when its use is continued, to diminish the frequency and force of the attacks. Dr. Copland¶ states that he has derived great benefit from it in Humoral Asthma and in Hooping-Cough. In the last-named disease, Dr. Fuller** obtained the best results from a combination of the Sulphate and Belladonna. To a child Aet. 3 he prescribes gr. 1/6th of Ext. Belladon. and gr. 1/2 of Zinci Sulph., four times daily. Above that age, 1/4 gr. of Belladonna and gr. j. of the Sulphate. Mr. Garraway also adopted the same treatment with great success in numerous cases of Hooping-Cough,

2858. In Intermittent Fevers, the Sulphate of Zinc has occasionally been used with success. Dr. Joseph Brown advises it to be combined with some ginger and conserve, each pill to con-tain gr. iij. of the Sulphate. Of these, two may be given thrice daily, during the intermissions; the number to be gradually increased as the stomach will bear it. It is advisable to avoid drinking immediately after the medicine has been taken, as it is apt to induce vomiting. Dr. Brown ranks Zinc next in value to Arsenic as an anti-periodic. Sir J. M'Grigor gave it to the soldiers in the Peninsular War, to the extent of 3ss. daily, with success. In Typhoid Fever, Dr. Heer* speaks undoubtingly of the beneficial action of the Sulphate, especially in allaying the nervous agitation: -2854 Therapeutic Uses 251 Zinci Sulph. gr. viiss., Aq. fviij., M. Dose, a tablespoonful every second hour.

* Guy's Hosp. Reports, Oct. 1846.

Lancet, Jan. 11, 1850.

Med. limes, Sept. 17, 1859.

§ Dr. Babington, op. cit.

|| Memoirs of Med. Society of London, vol. iii. p. 580. ¶ Dict. Pract. Med., vol. i. p. 152. ** Lancet, July 28,1860. Ibid., Oct. 17, 1863. Cyc. Pract. Med., vol. ii. p. 228.